A study in the “British Medical Journal” reviewed more than 10 studies, including the Women’s Health Initiative, looking at heart attack and stroke risk related to calcium supplements. Turns out, those who took these had a 10 to 30 percent higher risk.

The reason for that isn’t clear. Calcium can play a role in hardening of the arteries, but calcified arteries aren’t necessarily in danger of blockage.

In fact, plaques in blood vessels that can rupture and clot and cause a heart attack are less likely to do that if they contain calcium.

“No one is reaching this 100 percent firm conclusion that okay, you should not take calcium,” Dr. Farah continues. “The worst thing we could do right now is make everyone nervous every time they think about taking calcium.”

And for women with thin bones? Whether to take calcium comes down to looking at which of several possibilities is more likely.

The studies do not show an increased risk if the calcium comes from food, rather than supplements. The recommended dose is 1,000 to 1,500 milligrams a day. To get that much, you would have to eat three cups of yogurt, four cups of milk or five ounces of cheese.